1. Field of the Invention
The present invention relates to a device for retaining a boot on a gliding board. More specifically, the invention relates to the field of snowboarding.
2. Background and Material Information
When snowboarding, the user's feet are affixedly maintained on a board in a substantially transverse position with respect to the longitudinal direction of the board.
In contrast to alpine skiing boots, snowboarding must maintain a certain flexibility for reasons related to comfort as well as to the operation of the board. Indeed, turns ore taken by tilting the body towards the so-called front side or the so-called back side. These transfers of mass are accompanied by forward and/or sideward bending movements of the legs.
In a back side turn, a rigid portion supports the back of the snowboarder's leg and transmits the force from the leg to the board. It is a portion of the binding that ensures this role of rear support.
To accomplish certain ballet-type acrobatic movements and jumps, the snowboarder positions himself prone with respect to the board. Thus, he must be capable of bending his or her legs sideways, i.e., in the longitudinal axis of the board.
An example of a snowboard binding which fulfills the function of retaining a flexible boot while allowing a rear support, and which facilitates the lateral bending support, is provided in German Patent Publication No. DE-C2-36 22 746. This document discloses a so-called shell binding having a sole portion for receiving the boot that is extended rearwardly by a heel retaining portion, and on which a rear support element or rear spoiler is journalled. The journal is directed along a median longitudinal axis of the boot to enable sideways rocking of the dorsal support element when the snowboarder bends laterally.
Italian document MI92A/01238 has a retention device that is very similar to the German device, except that the journal is made by a rod mounted on a ball joint axle, the rear support being made by lateral tractional straps.
One of the problems associated with this type of device is that, in view of the free journal of the rear support element, to much flexibility is provided so that the user has the unpleasant feeling of totally lacking lateral support and of losing control when operating the board.